Probing magnetic anisotropy in epitaxial La0.67Sr0.33MnO3 thin films and nanostructures via planar Hall effect
Probing magnetic anisotropy in epitaxial La0.67Sr0.33MnO3 thin films and nanostructures via planar Hall effect
复制标题
DOI：
10.1117/12.2319249
复制
发表时间：
2018-09
期刊：
影响因子：
--
通讯作者：
Le Zhang;A. Rajapitamahuni;Yifei Hao;X. Hong
中科院分区：
文献类型：
--
作者：
Le Zhang;A. Rajapitamahuni;Yifei Hao;X. Hong
控制和操纵巨磁阻（CMR）氧化物（La，Sr）MnO 3（LSMO）的磁各向异性的能力是其在磁存储器应用中的实现的关键。在这项工作中，我们采用平面霍尔效应（PHE）作为一个强大的工具来探测LSMO薄膜和纳米结构的磁各向异性，其中的磁化强度太小，无法通过传统的磁力测量技术检测。通过分析的角度和磁场的PHE的依赖性，我们推导出一个面内双轴磁晶各向异性（MCA）的能量约为1.2 × 105 erg/cm 2的LSMO薄膜完全应变（001）SrTiO 3衬底。在LSMO中产生纳米级周期性深度调制建立了单轴各向异性，其具有显著增强的MCA能量密度，这归因于纳米结构中维持的高应变梯度。双轴和单轴MCA之间的能量竞争导致适当设计的LSMO纳米结构中的多级电阻切换行为，其可用于设计磁存储器件中的切换动力学。我们的工作点的外延应变在确定中巨磁阻氧化物的MCA的关键作用，并提供了一个有效的材料策略工程的磁性能的LSMO的新型自旋电子应用具有高热稳定性和高密度数据存储。
The ability to control and manipulate magnetic anisotropy in the colossal magnetoresistive (CMR) oxide (La,Sr)MnO3 (LSMO) is critical for its implementation in magnetic memory applications. In this work, we employ the planar Hall effect (PHE) as a powerful tool to probe the magnetic anisotropy in LSMO thin films and nanostructures, where the magnetization is too small to be detected by conventional magnetometry techniques. By analyzing the angular- and magnetic field-dependences of the PHE, we deduced an in-plane biaxial magnetocrystalline anisotropy (MCA) energy of ~1.2x105 erg/cm2 in LSMO thin films fully strained on (001) SrTiO3 substrates. Creating nanoscale periodic depth modulation in LSMO establishes a uniaxial anisotropy with substantially enhanced MCA energy density, which is attributed to a high strain gradient sustained in the nanostructure. The energy competition between the biaxial and uniaxial MCA leads to multi-level resistance switching behavior in properly engineered LSMO nanostructures, which can be utilized to design the switching dynamics in magnetic memory devices. Our work points to the critical role of epitaxial strain in determining the MCA in CMR oxides, and provides an effective material strategy for engineering the magnetic properties of LSMO for novel spintronic applications with high thermal stability and high density data storage.